Don't attempt a DRI2/Present page flip while the other one is flipping

Based on radeon commit 49f5b0bc301414df049e00d226034e3d6e56421b

Fixes corrupted display and hangs when switching between DRI2 and DRI3
fullscreen apps, e.g. a compositor using DRI3 and a fullscreen app using
DRI2 or vice versa.

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>

3 files changed, 34 insertions, 6 deletions

diff --git a/src/amdgpu_dri2.c b/src/amdgpu_dri2.c
index 1370551..756d6ad 100644
--- a/src/amdgpu_dri2.c
+++ b/src/amdgpu_dri2.c
@@ -528,6 +528,7 @@ static void
 amdgpu_dri2_flip_event_handler(ScrnInfoPtr scrn, uint32_t frame, uint64_t usec,
 			       void *event_data)
 {
+	AMDGPUInfoPtr info = AMDGPUPTR(scrn);
 	DRI2FrameEventPtr flip = event_data;
 	unsigned tv_sec, tv_usec;
 	DrawablePtr drawable;
@@ -572,6 +573,7 @@ amdgpu_dri2_flip_event_handler(ScrnInfoPtr scrn, uint32_t frame, uint64_t usec,
 		DRI2SwapComplete(flip->client, drawable, frame, tv_sec, tv_usec,
 				 DRI2_FLIP_COMPLETE, flip->event_complete,
 				 flip->event_data);
+		info->drmmode.dri2_flipping = FALSE;
 		break;
 	default:
 		xf86DrvMsg(scrn->scrnIndex, X_WARNING,
@@ -590,6 +592,7 @@ amdgpu_dri2_schedule_flip(ScrnInfoPtr scrn, ClientPtr client,
 			  DRI2BufferPtr back, DRI2SwapEventPtr func,
 			  void *data, unsigned int target_msc)
 {
+	AMDGPUInfoPtr info = AMDGPUPTR(scrn);
 	struct dri2_buffer_priv *back_priv;
 	struct amdgpu_buffer *bo = NULL;
 	DRI2FrameEventPtr flip_info;
@@ -616,10 +619,14 @@ amdgpu_dri2_schedule_flip(ScrnInfoPtr scrn, ClientPtr client,
 	back_priv = back->driverPrivate;
 	bo = amdgpu_get_pixmap_bo(back_priv->pixmap);
 
-	return amdgpu_do_pageflip(scrn, client, bo, AMDGPU_DRM_QUEUE_ID_DEFAULT,
-				  flip_info, ref_crtc_hw_id,
-				  amdgpu_dri2_flip_event_handler,
-				  amdgpu_dri2_flip_event_abort);
+	if (amdgpu_do_pageflip(scrn, client, bo, AMDGPU_DRM_QUEUE_ID_DEFAULT,
+			       flip_info, ref_crtc_hw_id,
+			       amdgpu_dri2_flip_event_handler,
+			       amdgpu_dri2_flip_event_abort)) {
+		info->drmmode.dri2_flipping = TRUE;
+		return TRUE;
+	}
+	return FALSE;
 }
 
 static Bool update_front(DrawablePtr draw, DRI2BufferPtr front)
@@ -698,8 +705,11 @@ static Bool
 can_flip(ScrnInfoPtr pScrn, DrawablePtr draw,
 	 DRI2BufferPtr front, DRI2BufferPtr back)
 {
+	AMDGPUInfoPtr info = AMDGPUPTR(pScrn);
+
 	return draw->type == DRAWABLE_WINDOW &&
-	    AMDGPUPTR(pScrn)->allowPageFlip &&
+	    info->allowPageFlip &&
+	    !info->drmmode.present_flipping &&
 	    pScrn->vtSema &&
 	    DRI2CanFlip(draw) && can_exchange(pScrn, draw, front, back);
 }
diff --git a/src/amdgpu_present.c b/src/amdgpu_present.c
index 75a4ba3..3db8cad 100644
--- a/src/amdgpu_present.c
+++ b/src/amdgpu_present.c
@@ -50,6 +50,7 @@
 
 struct amdgpu_present_vblank_event {
 	uint64_t event_id;
+	xf86CrtcPtr crtc;
 };
 
 static uint32_t crtc_select(int crtc_id)
@@ -222,6 +223,9 @@ amdgpu_present_check_flip(RRCrtcPtr crtc, WindowPtr window, PixmapPtr pixmap,
 	if (!sync_flip)
 		return FALSE;
 
+	if (info->drmmode.dri2_flipping)
+		return FALSE;
+
 	if (crtc) {
 		xf86CrtcPtr xf86_crtc = crtc->devPrivate;
 		drmmode_crtc_private_ptr drmmode_crtc = xf86_crtc->driver_private;
@@ -242,8 +246,12 @@ amdgpu_present_check_flip(RRCrtcPtr crtc, WindowPtr window, PixmapPtr pixmap,
 static void
 amdgpu_present_flip_event(ScrnInfoPtr scrn, uint32_t msc, uint64_t ust, void *pageflip_data)
 {
+	AMDGPUInfoPtr info = AMDGPUPTR(scrn);
 	struct amdgpu_present_vblank_event *event = pageflip_data;
 
+	if (!event->crtc)
+		info->drmmode.present_flipping = FALSE;
+
 	present_event_notify(event->event_id, ust, msc);
 	free(event);
 }
@@ -269,6 +277,7 @@ amdgpu_present_flip(RRCrtcPtr crtc, uint64_t event_id, uint64_t target_msc,
 {
 	ScreenPtr screen = crtc->pScreen;
 	ScrnInfoPtr scrn = xf86ScreenToScrn(screen);
+	AMDGPUInfoPtr info = AMDGPUPTR(scrn);
 	struct amdgpu_present_vblank_event *event;
 	xf86CrtcPtr xf86_crtc = crtc->devPrivate;
 	int crtc_id = xf86_crtc ? drmmode_get_crtc_id(xf86_crtc) : -1;
@@ -287,6 +296,7 @@ amdgpu_present_flip(RRCrtcPtr crtc, uint64_t event_id, uint64_t target_msc,
 		return FALSE;
 
 	event->event_id = event_id;
+	event->crtc = xf86_crtc;
 
 	ret = amdgpu_do_pageflip(scrn, AMDGPU_DRM_QUEUE_CLIENT_DEFAULT, bo,
 				 event_id, event, crtc_id,
@@ -294,6 +304,8 @@ amdgpu_present_flip(RRCrtcPtr crtc, uint64_t event_id, uint64_t target_msc,
 				 amdgpu_present_flip_abort);
 	if (!ret)
 		xf86DrvMsg(scrn->scrnIndex, X_ERROR, "present flip failed\n");
+	else
+		info->drmmode.present_flipping = TRUE;
 
 	return ret;
 }
@@ -305,6 +317,7 @@ static void
 amdgpu_present_unflip(ScreenPtr screen, uint64_t event_id)
 {
 	ScrnInfoPtr scrn = xf86ScreenToScrn(screen);
+	AMDGPUInfoPtr info = AMDGPUPTR(scrn);
 	struct amdgpu_present_vblank_event *event;
 	PixmapPtr pixmap = screen->GetScreenPixmap(screen);
 	struct amdgpu_buffer *bo;
@@ -326,8 +339,10 @@ amdgpu_present_unflip(ScreenPtr screen, uint64_t event_id)
 	ret = amdgpu_do_pageflip(scrn, AMDGPU_DRM_QUEUE_CLIENT_DEFAULT, bo,
 				 event_id, event, -1, amdgpu_present_flip_event,
 				 amdgpu_present_flip_abort);
-	if (!ret)
+	if (!ret) {
 		xf86DrvMsg(scrn->scrnIndex, X_ERROR, "present unflip failed\n");
+		info->drmmode.present_flipping = FALSE;
+	}
 }
 
 static present_screen_info_rec amdgpu_present_screen_info = {
diff --git a/src/drmmode_display.h b/src/drmmode_display.h
index d541d47..78ac9b7 100644
--- a/src/drmmode_display.h
+++ b/src/drmmode_display.h
@@ -54,6 +54,9 @@ typedef struct {
 	int count_crtcs;
 
 	Bool delete_dp_12_displays;
+
+	Bool dri2_flipping;
+	Bool present_flipping;
 } drmmode_rec, *drmmode_ptr;
 
 typedef struct {